nlohmann::json ToJson()

in src/iceberg/json_internal.cc [400:474]
71 lines of code
19 McCabe index (conditional complexity)

nlohmann::json ToJson(const Type& type) {
  switch (type.type_id()) {
    case TypeId::kStruct: {
      const auto& struct_type = static_cast<const StructType&>(type);
      nlohmann::json json;
      json[kType] = kStruct;
      nlohmann::json fields_json = nlohmann::json::array();
      for (const auto& field : struct_type.fields()) {
        fields_json.push_back(ToJson(field));
        // TODO(gangwu): add default values
      }
      json[kFields] = fields_json;
      return json;
    }
    case TypeId::kList: {
      const auto& list_type = static_cast<const ListType&>(type);
      nlohmann::json json;
      json[kType] = kList;

      const auto& element_field = list_type.fields().front();
      json[kElementId] = element_field.field_id();
      json[kElementRequired] = !element_field.optional();
      json[kElement] = ToJson(*element_field.type());
      return json;
    }
    case TypeId::kMap: {
      const auto& map_type = static_cast<const MapType&>(type);
      nlohmann::json json;
      json[std::string(kType)] = kMap;

      const auto& key_field = map_type.key();
      json[kKeyId] = key_field.field_id();
      json[kKey] = ToJson(*key_field.type());

      const auto& value_field = map_type.value();
      json[kValueId] = value_field.field_id();
      json[kValueRequired] = !value_field.optional();
      json[kValue] = ToJson(*value_field.type());
      return json;
    }
    case TypeId::kBoolean:
      return "boolean";
    case TypeId::kInt:
      return "int";
    case TypeId::kLong:
      return "long";
    case TypeId::kFloat:
      return "float";
    case TypeId::kDouble:
      return "double";
    case TypeId::kDecimal: {
      const auto& decimal_type = static_cast<const DecimalType&>(type);
      return std::format("decimal({},{})", decimal_type.precision(),
                         decimal_type.scale());
    }
    case TypeId::kDate:
      return "date";
    case TypeId::kTime:
      return "time";
    case TypeId::kTimestamp:
      return "timestamp";
    case TypeId::kTimestampTz:
      return "timestamptz";
    case TypeId::kString:
      return "string";
    case TypeId::kBinary:
      return "binary";
    case TypeId::kFixed: {
      const auto& fixed_type = static_cast<const FixedType&>(type);
      return std::format("fixed[{}]", fixed_type.length());
    }
    case TypeId::kUuid:
      return "uuid";
  }
}